The above is a link provided by Mike Rivest. It has links to newspaper ads with opening dates of San Antonio Theatres.
Newspaper ads were from San Antonio Light, San Antonio Evening News and San Antonio Express
Here is the movie page from the Express-News, March 19, 1949. Interstate still had the Empire, Texas Woodlawn, Laurel and Sunset. Statewide Drive Ins had just the Alamo and Mission. The Rigsby and the South Loop 13 were a year away. The Fredericksburg Road and Trail were still operated by U&E Theatres (Underwood & Ezell). The Alameda and Josephine were the two new kids on the block. The Olmos was to appear soon. No more indoor theatres were to come, until the 60s, when North Star Cinema (1964), The Wonder (1966), the Fox, and Century South (1969) came on the scene. There were to be a lot more drive ins though!